1. Technical Field
The present disclosure relates to a photoresist composition and a method of manufacturing a thin-film transistor substrate using the photoresist composition. More particularly, the present disclosure relates to a photoresist composition capable of forming a halftone photoresist film and a method of manufacturing a thin-film transistor substrate using the photoresist composition.
2. Description of the Related Art
A positive photoresist composition may be used for manufacturing a thin-film transistor (TFT) substrate using four masks. However, when a photoresist film is formed using a positive photoresist composition, the residual uniformity of the photoresist film corresponding to a channel portion may be poor, thereby resulting in a short circuit or a pixel defect. Furthermore, with the above mentioned conventional positive photoresist composition, a semiconductor layer may excessively protrude beneath source-drain electrodes, to decrease the aperture ratio of a display device. Consequently, skew may also be increased when etching processes are performed two or more times.
To overcome the above-mentioned difficulties, a method of manufacturing a TFT, which includes forming a photoresist film having an edge portion with a relatively high pattern angle, by using a negative photoresist composition has been developed. However, conventional negative photoresist compositions have relatively high contrast so that forming a halftone photoresist film by slit exposure may be difficult.
Thus, there is a need for an improved photoresist composition which is capable of forming a halftone photoresist film and to a method of manufacturing a thin-film transistor (TFT) substrate using this improved photoresist composition.